ELASTIC-PLASTIC FINITE-ELEMENT ANALYSIS OF DEEP-DRAWING PROCESSES BY MEMBRANE AND SHELL ELEMENTS

Both cylindrical cup drawing and square cup drawing are analyzed using both membrane analysis and shell analysis by the elastic-plastic fini te element method. An incremental formulation incorporating the effect of large deformation and anisotropy is used for the analysis of elast ic-plastic non-steady deformation. The corresponding experiments are c arried out to show the validity of the analysis. Comparisons are made in punch load and distribution of thickness strain between the mem bra ne analysis and the shell analysis for both cylindrical and square cli p drawing processes. In punch lend, both methods of analysis show very little difference and also show generally good agreement with the exp eriment. For the cylindrical cup deep drawing, the computed thickness strain of a membrane analysis, however, shows a wide difference with t he experiment. In the shell analysis, the thickness strain shows good agreement with the experiment. For the square cup deep drawing, both m embrane and shell analysis show a wide difference with experiment, thi s may be attributable to the ignorance of the shear deformation. Concl udingly, it has been shown that the membrane approach shows a limitati on for the deep drawing process in which the effect of bending is not negligible and more exact information on the thickness strain distribu tion is required.